the providing of good safety valves, gauge taps, glass water guages, pres sure thermometers, mercurial pressure guages, and the like, I am not aware that anything new and useful can now be offered; and am convinced that if due attention to these, could have insured entire safety, it would have been already attained. But an attentive consideration of the various accidents which have occurred within the circle of my observation, and of those also which have come to my knowledge through the publications of the day, has led me to the following conclusions:-First, that accidents, more or less serious, must be expected sometimes to attend the use of the steam engine, as well as all other efforts or combinations of human skill, and that the interests and safety of the public are not best promoted by resorting to a system of onerous and penal legislation in regulating its use. Second, that a very great proportion of the steam accidents which have occurred on both sides of the Atlantic, have been owing chiefly to defects in the general system of construction, and not, as has been very generally supposed, to the want of cautionary apparatus, or the gross neglect of those who were intrusted with the executive duties.

The last conclusion, though at variance with opinions which are exten: sively entertained, may also be sustained by a careful examination of the degree of strength which is afforded by the weakest portions of common steam boilers, as compared with the maximum pressure and incidental hazards to which they are liable. This want of a sufficient disparity between the maximum of force and the minimum of resistance, will appear still more obvious by extending the conparison to other structures or effective laboring machines of like inetal, where, in all important cases, it is believ ed, a much greater proportionate strength is usually found than pertains to steam boilers of the ordinary construction.

But however this may be, it appears certain that in this quarter, the ac cidents to steam boilers have been nearly in proportion to their deficiency in comparative strength. This point deserves, however, a more complete elucidation than can be attempted at this time, and I therefore refer to a communication to the Hon. Secretary of the Treasury of the United States on the general subject, which I prepared a few months since in compliance with a resolution of inquiry which was passed by Congress; a copy of the same is hereto annexed, marked [B.]*

It is obvious that there are few uses to which metals are applied, which demand so much attention to strength and security, as in the manufacture of steam boilers. These should be so constructed as to be guarded, on this point, against all contingencies of use which are likely to occur.

If an examination of the English and American steam vessels should show a degree of deficiency on this point, the cause may be readily found in the influence of habit, of prevailing opinions and of previous examples, which have had their origin in an early stage of the art; and also in considerations of practical convenience and facility of manufacture. That the warnings resulting from the various disasters which have occurred, have failed to some extent in their preventive effects, is probably because the theoretical opinion has been honestly and seduously cherished, that these accidents have occurred only through the culpable carelessness and neglect of those in immediate charge of the boilers; and the evil is thus in some degree rendered permanent.

That the safety of steam boilers from explosions does not necessarily depend upon working with so low a pressure as five or seven pounds to the square inch, and that a reasonable increase in the proportionate strength of the boilers in steam vessels would remove all immediate hazard, and

For a revised copy of this communication see Appendix [B.]

nearly end the catalogue of these disasters, is rendered apparent by the facts which relate to this branch of navigation as it has been carried on in various directions from the city and port of New York. Here, where stearn navigation was first successfully established, and where it has probably attained its highest degree of efficiency, we might have expected that accidents and disasters would, not unfrequently, attend the use of a power at once so novel and energetic. The accidents and fatalities which have here occurred, as well as their probable proportion to the pressure of steam, the number of boats employed or trips made, the number of miles navigated, and the number of passengers which from time to time have been exposed, may be seen in the annexed table,

This table, so far as relates to the service performed on the different routes and the number of persons exposed, is made up approximately, by estimates founded on my general acquaintance with our steam navigation; but is believed to be sufficiently correct for general purposes. I have separated the business of the fifteen years which it comprises, into three several periods of five years each; commencing with 1824; early in which year the navigation in this State, which had previously been controlled by the associates of Fulton and Livingston, was thrown open to public competitors.

It appears from the average results of this table, that during even the first period of five years after the navigation was thrown open to public competition, the ratio of steam accidents was only equal to one, for more than 20,000 trips or passages; and that the average loss of life is only equal to one, for more than 126,000 passengers exposed. Thus, at the fair outset of this noble enterprise, a degree of safety was attained for the passenger, such as may well challenge comparison with any artificial means of transit or locomotion that have ever been resorted to by the human race. It appears further, on comparing the results for these several periods, that the ratio of steam accidents for the first and third periods, as compared with the probable number of trips made, has decreased from one in 20,317 for the first period, to one in 317,105 for the third or latest period; showing a diminution of the ratio of accidents in the average period of ten years equal to about 84 per cent. The ratio of lives lost from these accidents during the same period, has also decreased from one in 126,211 to one in 1,985,787; equal also to a diminution in the ratio of personal hazard, in this short period, of 84 per cent.

It appears also from this table, that during the first of these periods, the average number of miles navigated by all our steamboats, to each explosion which occurred, was equal to 235,646; a distance equal to many times the circumference of our globe, and about equal to that from the earth to the moon. But even this ratio has been rendered tenfold more favorable in the short average period of ten years, being for the latest five years, 2,733,725 miles navigated for each explosion; or more than eleven times the distance from the earth to the moon; and reducing the ratio of hazards in proportion to distance, almost 90 per cent.*

[The results of a like examination extended to the whole Atlantic tide waters, and the great lakes, it is believed, would be no less favorable. But it will doubtless be supposed, that on our western rivers the ratio of accidents and hazard by steam explosions must have been far greater. This is probably true, in a degree; owing to the ultra and improvident system of high pressure construction which there prevails. But let the inquiry be strictly made, upon the above principles of analysis, and it may serve to show how uncertain a test of the real hazard is found in public prejudice, or individual apprehesion. The constructors and managers of western engines and steamboats owe it to themselves, to their profession and the public, to make this inquiry; so that the faults, or the safety of their favorite system of engineering may fully appear. If a scheme of penal enactments shall there be found necessary and available for the protection of human life, which I cannot readily believe, let it be confined to those waters which are above the flow of the tide; or, which I deem better and more efficient practice, let their present system be either modified or discontinued.]

First period, from 1824 to 1828, both inclusive.

500 50 2,500 185,000

1,800, 288,000) 144,000

A Tabular Estimate of the amount of Steam Navigation connected with the Port of New York, the number of passengers carried, and the steam accidents, together with the average anh comparative hazards which have attended the same, for five years, beginning with 1834 and ending with 1838.

*The miscellaneous business is doubtless greatly underrated.

a Constitution.

b Franklin.

c Jersey.

h Ch. J. Marshall; Ohio.

i General Jackson.
United States.

d Etna, (high pressure,) Bellona, Legislator.k New England.

e Hudson.

fOliver Ellsworth.

Average number of miles navigated to each lexplosion,

1 Novelty, high pressure, 1837.

843,240

g Fidelity, Patent, Caroline, Average number of miles navigated to each s William Gibbons, January, 1836. explosion, Average miles to each explosion, 2,733,725

235,646

[N. B. Accidents other than by steam were not included in the above Table; only one of a fatal character being recollected, which happened at sea. The calamitous loss of the Lexington, at a more recent period, will doubtless inspire additional caution in all future navigation. In reference to the comparative and increasing safety of steam navigation, which may be deduced from the above Table, it is proper to notice, that a large portion of the above consists of a regular and unremitted night navigation, which is carried on in every variety of weather.]

This remarkable diminution of accidents and hazard, it may be seen, has taken place in the very period in which the average working pressure of steam has been more than doubled. It has also been attained solely by

professional skill and experience, and without any aid from legislative in-. terference; for the law of Congress on this subject was not in force till near the close of the year 1838. Had such a system of legeslation been at first adopted, there are sound reasons for concluding that it would not have prevented disasters, but might have greatly retarded the rapid advance in safety, as well as improvement, which has been so happily attained.*

It must not be supposed, however, that the average pressure of steam now used on the New York steamboats can be generally increased withbut incurring material hazard. The thickness which is found most suitable for boiler metal and the practical and economical limits of form and size, are such as should prevent us from allowing a maximum pressure exceeding one and a half or two atmospheres above the common boiling point, for condensing engines; with an addition of about one atmosphere for high pressure engines, which are worked without a condenser and air pump. To these limits, if an adequate system of boiler construction be adopted the pressure may with safety be carried, as is done in locomotive engines, in the use of which, owing to a better system of construction, fatal accidents have been less frequent, perhaps, than with low pressure marine engines.

I annex also a copy of the law of the United States, entitled, " An Act to provide for the better security of the lives of passengers on board of vessels propelled in whole or in part by steam."

It may be proper to remark, that the passage of this law was unexpect ed to the owners of steam vessels, and that it appears to have been considered by Congress itself as a premature measure, as may be inferred from the resolutions for instituting an inquiry on this subject which were passed at the same period.

* [January, 1840. On the 13th of the present month, the steamboat Lexington took fire on Long Island Sound and was destroyed. By this frightful disaster 124 lives were lost, and only four persons escaped. The loss of this vessel was, perhaps, owing to the combustible nature of the materials in which the fire broke out, the want of immediate and concerted action to arrest its fatal progress, and the panic which appears to have prevailed on board. To these circumstances, and especially to the latter, is ascribed the extraordinary destruction of life; all the boats having been lowered and lost while the engine was running at full speed.

The loss of a large amount of property by the owners and managers of the Legington, and the destruction of thirty-nine valuable lives of persons in the service, might have shown that no reasonable motive or provision was likely to have been wanting to secure safety for all on board, whatever may have been the momentary errors or indiscretions of the crew or passengers. Those who have labored to inflame the public against these unfortunate men may well be reminded, that it is now thirty years since the public have enjoyed the use of passenger vessels impelled by fire and steam, and that during this period not less than thirty millions of persons have been transported from time to time, in the various steamboats which have to run to and from the City of New York, and that these steamboats probably navigated a distance equal to fifteen millions of miles, and that in all this prolonged and varied exposure, never before has a single life been lost by the burning of a steamboat. This fact alone, to the unprejudiced, speaks volumes in favor of the general care and skill of the parties who have been concerned in this species of navigation.]